| Characteristic | N = 35,5381 |
|---|---|
| Dataset | |
| Part 139 Airports | 532 (1.5%) |
| EPA Stewardship Program Participating Facilities | 16 (<0.1%) |
| Facilities in Industries that may be Handling PFAS | 31,902 (90%) |
| Federal Agency Locations with Known or Suspected PFAS Detections | 694 (2.0%) |
| Fire Training Sites | 448 (1.3%) |
| Facilities that Manufacture or Import PFAS | 807 (2.3%) |
| Superfund Sites with PFAS Detections | 894 (2.5%) |
| Known PFAS Spills/Release Incidents | 245 (0.7%) |
| 1 n (%) | |
Exposures to per- and polyfluoroalkyl substances in environmentally overburdened communities
A. Hernandez
April 11, 2023
Background
- PFAS are ubiquitous in the environment, but the scope of contamination in the US is still broadly unknown
Motivating question
What are the characteristics of communities that are more exposed to PFAS through drinking water? Are exposures to PFAS in drinking water greater in environmental justice communities?
Background cont.
UCMR3 was the first and only national assessment of PFAS in PWSs to date
- Testing was limited in scope (5 PFAS), high detection limits, not all PWSs represented
- UCMR 5 testing will be more expansive, not completed until 2025
- New EPA NPDWR will require more regular testing for 6 PFAS compounds
Some states have more expansive testing programs, but this work is incomplete, inconsistent, resource intensive.
Background cont.
Matching limited PWS monitoring data to demographic information presents a number of challenges, largely due to the lack of availability of information on service area boundaries at a national scale.
- Spatial matching happens at the county level, but PWSs rarely serve an entire county.
Background cont.
How else might we assess exposure to PFAS?
- Proximity to PFAS contamination sites is associated with detections of PFAS in drinking water (Hu et al. 2016)
- Consumption of PFAS contaminated drinking water is associated with higher blood levels of PFAS (Post et al. 2021).
Background cont.
What is considered a “PFAS contamination site”? What facilities are using PFAS?
In the absence of comprehensive testing data, communities, researchers, and policymakers have turned to conceptual approaches which precautionarily consider certain types of facilities as “presumptive” or “potential” PFAS point sources
- Presumptive facilities include wastewater treatment plants, current and former military sites, airports, and certain industrial facilities.
Study design/goals
Goal:
- Assess the relationship between environmentally overburdened communities and PFAS point sources + contamination sites
Design:
- Aggregate information about PFAS point sources and contamination sites
- Match sites to a census tract
- Assess socio-demographic and environmental characteristics at the census tract
PFAS point sources + contamination sites
PFAS point sources + contamination sites
Measuring/assessing environmental justice
EJ research on exposures to contaminants in drinking water has primarily relied on county-level demographics or has been limited to state-specific assessments for states with more comprehensive water system data.
This work has historically relied on unidimensional measures of socioeconomic status and race to evaluate disparities in environmental exposures.
Measuring/assessing environmental justice cont.
The Environmental Justice Index (EJI), developed by CDC and ATSDR, is a multi-dimensional index that accounts for cumulative exposures and disproportionate health outcomes
Compares census-tract level environmental, social, and health-based community indicators
Unlike EPA’s EJSCREEN and CDC’s Social Vulnerability Index, the EJI quantifies the cumulative impact of environmental burdens on health
Created to help identify communities experiencing disproportionate health outcomes associated with environmental exposures
Environmental Justice Index
Environmental Justice Index
The EJI underrepresents the health burden from exposures to contaminants (broadly, including PFAS) in drinking water and exposures to PFAS from other sources
- This is mostly due to spatial mismatches/data incompleteness, but also because PFAS testing is limited and PFAS are generally unregulated/underreported
EJI does incorporate info about TRI reporting facilities (proportion of a census tract that falls within a 1-mile buffer of a TRI facility).
- PFAS were added to the TRI program in 2020, however, only 39 facilities reported PFAS emissions in 2020, which is likely a substantial underestimation (Post et al. 2021, Reade et al. 2022).
Environmental Justice Index: Environmental Burden Module
Calculating the Env Burden:
Order the census tracts on a scale from 0 to 100 for a given variable to create a percentile rank for the percentage of tracts equal to or lower than the burden for that variable (0-1 index).
- For variables like TRI sites, the metric is a proximity measure: the percent of the tract within 1-mile of a TRI site
An overall rank for each module is created by summing the individual variables within the module and repeating the percentile ranking process.
This is repeated again with the other two modules to calculate an EJI Rank